1. Field of the Invention
The invention relates to a method and apparatus for extracting mechanical energy from a pressured gas by expanding same in a plurality of peripherally spaced cylinders mounted for rotational movement about the axis of an output shaft which is co-rotatably connected to the cylinders.
2. Description of the Prior Art
The great majority of rotary engines designed for operation by a pressured gas, including a pressured gas developed by internal combustion of a mixture of a combustible fuel and air, have utilized linearly reciprocating pistons and cylinders. In most instances, the cylinders were stationary and the pistons were connected by connecting rods to a rotary crank shaft which provided the output power of the engine. The desirability of mounting a plurality of cylinders to a body which is co-rotatable with the output shaft has been disclosed in prior patents, see for example, U.S. Pat. No. 4,420,945 to DIBRELL. In such prior patent, however, a free piston is employed and, according to computer evaluations of the DIBRELL design, the overall efficiency of the device to produce mechanical energy in rotational form is not competitive with conventional forms of fluid pressure actuated piston engines. There is no question, however, but that energy is extracted from the pressured gas supplied to the cylinder. The problem is the efficient conversion of the extracted energy into a rotational form, without employing the expensive crank shaft and connecting rod constructions of the prior art.